Suchergebnisse

With the fast increase of world-wide consumption and lack of legislation of engineered nanomaterials (ENMs), it is expected an increase of artificial production and consequently, an increase of the number of nanoparticles (NPs) that are released into the environment. Most nanoparticles present in the aquatic environment, such as those of titanium oxide nTiO2, have effects on histopathological alterations on fish, creating several implications on their health, and, consequently influencing aquatic environment status. The effects caused by the exposure to two realistic concentrations of nTiO2 (20 and 200 μgL-1, plus controls) were evaluated in gills of fish (S. senegalensis), through a short-term ex vivo approach, meaning that exposure was accomplished after dissection of gills from the animals. Alterations in gills were analysed, such as the formation of metal deposits and the specific alterations to gas-exchange epithelial and chloride cells. Standard histological techniques were coupled with fluorescent techniques to assess aforesaid alterations. Quantitative ad semi-quantitative approaches were employed. Overall, the main alterations observed in gill exposed to nTiO2 treatments were epithelial lifting, chloride cells autolysis and goblet cell hypertrophy. Higher severity and dissemination of alterations was observed for gills exposed to the highest concentration (200 μg nTiO2 L-1). In accordance, the gill global histopathological condition indice (Ih) increased with the increase of nTiO2 concentration in water at T2 and T4. The number of CC (Chloride cells) and GC (Goblet cells) per interlamellar space also increased with the exposure to nTiO2, at T2, however without a clear relationship with the concentration. Metal deposits were found in gill macrophages, distributed consistently trough all treatments, failing to demonstrate any cause-effect relation between concentrations and time of exposure. Overall, the present study indicates that under ecologically-relevant concentrations of nTiO2 caused moderately histopathological lesions in gills of S. senegalensis. Although, the alterations in mucocytes indicated responses to the challenge, the exposure to TiO2 promoted osmotic imbalance. The present ex vivo study significantly contributed to define further procedures to nanotoxicity studies.

Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2016 ; The SG concept arises from the fact that there is an increase in global energy consumption. One of the factors delaying an energetic paradigm change worldwide is the electric grids. Even though there is no specific definition for the SG concept there are several characteristics that describe it. Those features represent several advantages relating to reliability and efficiency. The most important one is the two way flow of energy and information between utilities and consumers. The infrastructures in standard grids and the SG can classified the same way but the second one has several components contributing for monitoring and management improvement. The SG's management system allows peak reduction, using several techniques underlining many advantages like controlling costs and emissions. Furthermore, it presents a new concept called demand response that allows consumers to play an important role in the electric systems. This factor brings benefits for utilities, consumers and the whole grid but it increases problems in security and that is why the SG relies in a good protection system. There are many schemes and components to create it. The MG can be considered has an electric grid in small scale which can connect to the whole grid. To implement a MG it is necessary economic and technical studies. For that, software like HOMER can be used. However, the economic study can be complex because there are factors that are difficult to evaluate beyond energy selling. On top of that, there are legislation and incentive programs that should be considered. Two case studies prove that MG can be profitable. In the first study, recurring to HOMER, and a scenario with energy selling only, it was obtained a 106% reduction on production cost and 32% in emissions. The installer would have an $8 000 000 profit in the MG's lifetime. In the second case, it was considered economic services ...

Pharmaceuticals and personal care products (PPCPs) are widely used on a daily basis. After their usage they reach the wastewater treatment plants (WWTPs). These compounds have different physico-chemical characteristics, which makes them difficult to completely remove in the WWTPs, througth conventional treatments. Currently, there is no legislation regarding PPCPs thresholds in effluent discharge. But, even at vestigial concentrations, these compounds enclose environmental risks due to, e.g., endocrine disruption potential. There is a need of alternative techniques for their removal in WWTPs. The main goal of this work was to assess the use of electrodialytic (ED) process to remove PPCPs from the effluent to be discharged. A two-compartment ED cell was used testing (i) the effluent position in the cell (anode and cathode compartment); (ii) the use of anion (AEM) and cation exchange membrane (CEM); (iii) the treatment period (6, 12 and 24 hours); (iv) effluent recirculation and current steps; (v) the feasibility of sequential treatments. Phosphorus (P) removal from effluent and energetic costs associated to the process were also evaluated. Five PPCPs were studied – caffeine (CAF), bisphenol A (BPA), 17 β-estradiol (E2), ethinyl estradiol (EE2) and oxybenzone (MBPh). The ED process showed to be effective in the removal when effluent is in the anode compartment. Oxidation is suggested to be the main removal process, which was between 88 and 96%, for all the compounds, in 6 hours. Nevertheless, the presence of intermediates and/or by-products was also observed in some cases. Effluent recirculation should have a retention time in the ED cell big enough to promote removal whereas the current steps (effluent in anode compartment) slightly increased removal efficiencies (higher than 80% for all PPCPs). The sequential set of ED treatment (effluent in anode compartment) showed to be effective during both periods with a removal percentage between 80 and 95% and 73 to 88% in the case of AEM and CEM, respectively. Again, the main removal process is strongly suggested to be oxidation in the anode compartment. However, there was an increase of BOD5 and COD, which might be explained by effluent spiking, these parameters limiting the effluent discharge. From these treatments, the use of AEM, enhanced the P removal from effluent to minimize risk of eutrophication. Energetic costs of the best set-up (6 hours) are approximately 0,8€/m3 of wastewater, a value considered low, attending to the prices of other treatment processes.

The ocean's vastness holds still many unexplored organisms with unique adaptive features that enable them to thrive in their environment. Eulalia viridis is one of them. This uncanny bright green worm is a predatory marine Polychaeta of the rocky intertidal that lacks jaws, but it is equipped with a toxin-containing mucus that enables predating larger invertebrates from which soft tissue is extracted through suction. Motivated by the high-value of toxins as bioreactives and by the European Union's ambitions of leading the Blue Growth Strategy, for which Portugal's vast EEZ offers high perspectives; a case-study to explore the biotechnological potential of this species was undertaken. The worm's microanatomy revealed key adaptations for feeding such as special sensorial papillae and cells responsible for the secretion of mucus and toxins. Whole-transcriptome sequencing and toxicity assays yielded a complex pattern of proteinaceous toxins and enzymes with several functions: tissue permeabilization, coagulation impairment and blocking of neuromuscular activity. The main neurotoxins, "phyllotoxins", found to be cysteine-rich proteins, act as immobilising agents against mussels and other invertebrate prey and are delivered by contact with mucus. In turn, higher toxicity towards ovarian cancer cell line (A2780) than normal cells, involved cytotoxic and cytostatic properties through cell cycle arrest and extrinsic programmed cell death. Several proteins involved in these effects were identified by combining transcriptomics and proteomics. The worm's mucosecretions also hold internalisable proteinaceous complexes that display fluorescent properties and whose emission is reversibly switched by redox status. Altogether, the features found in the secretions of a single species disclose the immense biotechnological potential of marine annelids, and invertebrates in general, as source of valuable bio-reactives, even in temperate waters. The methodological pipeline, combining ecology, toxicology and molecular biology, circumvented many difficulties of marine bioprospecting and is an important contribution for the sustainable exploitation of novel marine bioresources. ; O oceano contém muitos organismos por explorar com características adaptativas que os permitem prosperar no seu meio ambiente. Eulalia viridis é um desses organismos. Esta poliqueta verde clara é predador do intertidal rochoso sem mandibulas, equipado dum muco tóxico, permitindo assim predar invertebrados maiores extraindo pedaços de tecido através da sucção. Motivado pelo valor das toxinas como substâncias bioreactivas e pela ambição da UE de conduzir a Estratégia para o Crescimento Azul, à qual a vasta ZEE portuguesa oferece grandes perspetivas, o potencial biotecnológico desta espécie foi analisado. A análise microanatómica desta minhoca revelou adaptações cruciais na alimentação: existência de papilas sensoriais e células responsáveis pela secreção de muco e toxinas. A sequenciação completa do transcritoma e ensaios toxicológicos revelaram um complexo padrão de toxinas proteicas e enzimas com diversas funções: permeabilização de tecidos, anti-coagulação e bloqueio da atividade neuromuscular. As principais neurotoxinas da Eulalia, "filotoxinas", são proteínas ricas em cisteínas, que atuam como agentes imobilizadores em mexilhões e outros invertebrados, que são administradas por contacto através do muco. Por sua vez, uma maior toxicidade para com a linha celular do cancro do ovário (A2780) do que células normais, demonstraram propriedades citotóxicas e citoestáticas através da paragem do ciclo celular e indução de morte celular programada pela via extrínseca. As proteínas responsáveis por estes efeitos foram identificadas, através de transcritómica e proteómica. As secreções mucosas da minhoca contêm também complexos proteicos internalizáveis que apresentam fluorescência, cuja emissão é reversivelmente regulada pelo estado redox. Resumindo, as características encontradas nas secreções de uma espécie demonstram o vasto potencial biotecnológico de anelídeos marinhos, como uma fonte valiosa de bioreactivos, mesmo em águas temperadas. O percurso metodológico utilizado, a combinação da ecologia, toxicologia e biologia molecular, permitiu contornar dificuldades da bioprospecção marinha, revelando ser um importante contributo para exploração sustentável de novos biorecursos marinhos.

This work would not have been possible without the INTERREG SUDOE project 4KET4REUSE - KETs for the removal of emerging contaminants in treated wastewater from the SUDOE area (SOE1/P1/E0253, 2016 – 2019) that funded most of it, which I deeply acknowledge. The Department of Civil Engineering from the Technical University of Denmark (DTU) is also acknowledged for the funding of the study of the arsenic and petroleum hydrocarbons removal from soil. This work has also received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045, the IDS-FunMat-INNO Doctoral Programme funded by the KIC EIT-Raw Materials, the Portuguese Polar Programme-PROPOLAR, the Erasmus+ scholarship, which all were a great contribution to carry out this work. ; Soil and water resources are interconnected, and their protection is essential to Human life. Emerging organic contaminants (EOC) are a large group of unregulated compounds, which presence in both soils and effluents is a matter of major concern with unknown consequences. Thus, in order to reduce environmental and human associated risks, there is a need to develop viable techniques for the removal of these contaminants. In this Ph.D. dissertation, cost-effective key solutions based on electro-technologies were designed and studied for soil and effluent remediation, which are the downstream and upstream sources of the contamination. Soil remediation was focused on EOC and contamination legacy that is more resistant to natural attenuation (arsenic and petroleum hydrocarbons). The effluent treatment was focused on EOC removals and also the possibility to promote phosphorus recovery/reuse, a critical raw material essential to life. The electrokinetic contaminants removal from soil was developed aiming its valorization either in agriculture or as a secondary raw material. Soil treatment was highly dependent on both soil and contaminants properties. More aggressive electro-treatment conditions were designed ex-situ using 1-to 3-compartment electrodialytic reactors with soil stirring. For all the cases, the electric current enhanced contaminants removal. Up to 80% of arsenic was removed from soil in a 2-compartment cell, whereas remediation experiments of EOC achieved at least a 44% removal (mobilized and/or degraded) for three tested set-ups. An in-situ treatment with different electrical current strategies aiming at less soil disturbance was also developed for more sensitive scenarios like agricultural soil and arctic environment. The removal of hydrocarbons in artic soil was challenged by a more recalcitrant contamination, whereas EOC remediation in agricultural soil was enhanced up to a 37% by the electric current. The electro-technologies developed for effluent treatment were designed to promote a safer irrigation and/or environmental discharge. For either the reuse or the removal of phosphorus, together with EOC removal, a reactor with an anion exchange membrane with polarization switch showed to be the best approach developed (up to 15% P recovery and 57-72% of EOC removal). A one-compartment reactor with a sequence of more than two circular-shaped metal mixed oxide coated titanium mesh electrodes, alternated in polarity, was the best approach for EOC removal (up to 90% in 2 hours). This treatment does not require the addition of reagents and represents low energetic costs, making it more environmentally friendly. The technologies based on electrokinetic treatment showed to have a high potential for a wide array of applications, although the selection of the suitable treatment setup should be done case-by-case.

Toxicity tests on complex wastewater effluents have been considered as an important complement to emission limit values (ELV) based on physico-chemical and microbiological parameters in recent years. However, relatively few studies have been conducted so far evaluating the toxicity of effluents with aquatic organisms, and it remains unclear which test species should be used in such evaluations. The first aim of this dissertation was therefore to assess the potential of the crustacean Daphnia magna as a bioindicator for the toxicity of a domestic effluent disinfected with peracetic acid (PAA), a disinfect that has received increasing attention in recent years as an alternative disinfectant for chloride. To this end, bioassays were performed with D. magna on the secondary effluent from the WWTP of Beirolas, with and without disinfection by 5 mg.L-1, 10 mg.L-1 and 15 mg.L-1 PAA. These PAA concentrations were selected since they were shown in a parallel MSc study to have high removal efficacy of coliform and faecal bacteria. Exposure to the secondary effluent without disinfection caused no mortality or immobility on the organisms. Although the disinfected effluent adhered to all the standards set in current Legislation, even the lowest PAA concentration resulted in 100% daphnid mortality within 48h. Subsequently, efforts should be made to evaluate whether lower PAA concentrations or a longer residual time after PAA treatment may ensure disinfection efficacy without exerting toxicity to aquatic organisms like D. magna. The second aim of this dissertation was to compare the sensitivity of D. magna to wastewater with that of other species commonly used in bioassays. This was done to evaluate which test species are the most appropriate for use in wastewater toxicity testing. To this end, a literature search was conducted by collecting data from papers where the toxicity of effluents was tested to D. magna and at least one other species. This thus allowed to evaluate the relative tolerance (Trel) of these species as compared to D. magna. The taxonomic groups that appeared to be more sensitive to effluents than D. magna were bacteria and rotifers. On the other hand, macrophytes, insects and fish were found to be generally less sensitive than D. magna. Since no single species was aways the most sensitive species to the wide range of effluents (e.g. different sources, compositions and sampling periods) included in the dataset, a test battery including species from different taxonomic groups is recommended for effluent testing.

Food waste is a serious ethical, environmental and economic problem of excessive contemporary consumerism. The European Union (EU) estimates that around 88 million tonnes of food are wasted annually, with associated costs estimated at 143 billion euros. Food waste occurs in all phases of the food supply chain, starting with producers and ending with consumers, and this food waste has a staggering environmental impact. There are several factors which contribute to excessive quantities of wasted food. Some are related to current production systems and product commercialization, including food quality and security norms, others are more personal like people's food habits, awareness, values and consumer attitudes in regards to consumption and food waste. In order to implement policies, strategies and measures which contribute to reducing food waste on the consumer level there is a need to understand the factors which shape consumer behaviours. Starting with the models and variables indicated in the literature overview, possible determinants of environmental behaviour were presented. Through these variables the study seeks to estimate if there is a differences between consumers in countries with different contexts and food habits by choosing Poland and Portugal as the case studies. The main differences between these countries lies in two key aspects which could have an influence not only on the behaviour related to consumption and wasting food but also on self-awareness and attitudes towards the problem. On the one hand Poland is one of the most agricultural country in the EU, while Portugal has already lost much of its agricultural production, whilst on the other hand, Polish and Portuguese food habits are different. To achieve these objectives in terms of methodology, an online survey was created. The survey was translated into Polish and Portuguese and its goal was to understand the reasons for food waste, purchasing behaviour, attitudes, the level of consumer knowledge and opinions with respect to food waste, as well as perception about the quantities of wasted food in the consumer's household. Based on responses obtained in the survey in which 232 Polish and 244 Portuguese consumers participated, the conclusion is that despite the different contexts and food habits some of the behaviours and opinions are similar, namely the motives for throwing food away and opinions about the measures which could be taken to reduce food waste. Through the analysis, the results have shown that Polish consumers waste more than Portuguese and have less positive attitudes towards food waste than Portuguese consumers. Furthermore, the Polish seem to attribute less importance to the food waste problem and have less knowledge about food waste. These differences could be not only due to different contexts and food habits but also to the types of campaigns and initiatives which Governments and Governmental organizations from both countries have implemented.

Phosphorus (P) is becoming a scarce element due to the decreasing availability of primary sources. Therefore, recover P from secondary sources, e.g. waste streams, have become extremely important. Sewage sludge ash (SSA) is a reliable secondary source of P. The use of SSAs as a direct fertilizer has very restricted legislation due to the presence of inorganic contaminants. Furthermore, the P present in SSAs is not in a plant-available form. The electrodialytic (ED) process is one of the methods under development to recover P and simultaneously remove heavy metals. The present work aimed to optimize the P recovery through a 2 compartment electrodialytic cell. The research was divided in three independent phases. In the first phase, ED experiments were carried out for two SSAs from different seasons, varying the duration of the ED process (2, 4, 6 and 9 days). During the ED treatment the SSA was suspended in distilled water in the anolyte, which was separated from the catholyte by a cation exchange membrane. From both ashes 90% of P was successfully extracted after 6 days of treatment. Regarding the heavy metals removal, one of the SSAs had a better removal than the other. Therefore, it was possible to conclude that SSAs from different seasons can be submitted to ED process under the same parameters. In the second phase, the two SSAs were exposed to humidity and air prior to ED, in order to carbonate them. Although this procedure was not successful, ED experiments were carried out varying the duration of the treatment (2 and 6 days) and the period of air exposure that SSAs were submitted to (7, 14 and 30 days). After 6 days of treatment and 30 days of air exposure, 90% of phosphorus was successfully extracted from both ashes. No differences were identified between carbonated and non-carbonated SSAs. Thus, SSAs that were exposed to the air and humidity, e.g. SSAs stored for 30 days in an open deposit, can be treated under the same parameters as the SSAs directly collected from the incineration process. In the third phase, ED experiments were carried out during 6 days varying the stirring time (0, 1, 2 and 4 h/day) in order to investigate if energy can be saved on the stirring process. After 6 days of treatment and 4 h/day stirring, 80% and 90% of P was successfully extracted from SSA-A and SSA-B, respectively. This value is very similar to the one obtained for 6 days of treatment stirring 24 h/day.

Food security, which affects mainly developing countries, is a worldwide problem that has called the attention of the economic, political and scientific community. Achieving food security is a very complex process that involves not only the ability of farming but also a constant adaptation to natural phenomena, as for example, rainfall patterns. Limited knowledge and access to information and technologies, restrict the capacity of local farming communities to achieve food security. Furthermore, there is a lack of suitable methods and tools for involving stakeholders, such as farmers, in the development and assessment of food policies and their long-term system-wide effects. The main goal of this research is to investigate how the use of mixed-methods – scenarios and participatory System Dynamics (SD) modelling – are capable of improving understanding and an integrative view of food systems, serving as a lever for supporting food security decision-making processes. Additionally, this research aims to answer the following two questions: i) How can scenarios and participatory SD be used together to study plausible futures of food security involving smallholder farmers in developing countries?; ii) What are the possible policy pathways to avoid undesirable situations and to stimulate desirable ones, in a context of subsidence farming in Sub-Saharan African countries?. For this specific purpose, a group of smallholder farmers in Zambia was analyzed as a case study. First, a workshop was implemented in which a scenario of poor rainfall and no government help was developed. In order to achieve food security, participants had to find policy proposals and pathways to avoid or to overcome this undesired scenario. Subsequently, from the scenario workshop data, causal loop diagrams (CLD) were built using a systematic coding process. The next steps were to analyse policy proposals through a cross-impact analysis and develop an outline of pathways to study the complementarity and compatibility of such proposals. The 11 policy proposals were Charcoal Business; Livestock Business; Groundnuts Business; Gardening; Loan; Piecework; Land (productive land); Rental Business; Partnership; Legislation for Deforestation/Afforestation; and, Retention Basins/Drilling Boreholes. Finally, it was possible to design an innovative Action Plan that shows the pathways and the pace at which each proposal may achieve food security. It was concluded that scenario workshop and participatory SD may tightly coupled since these methods complement each other, stimulating system thinking and co-creation of knowledge. Scenario workshops are a disruptive and exploratory method, as it allows to elicit creative and plausible images from participants. Participatory SD supports decision-making processes by analysing policy proposals and its pathways, leading to the elaboration of joint action plans. In the Zambian case, from the 11 plausible policy proposals, it was found that Piecework enables a swifter path to achieve food security, while Rental Business would be the slowest. Additionally, it was found that some of the policy proposals could be reinforced if implemented together, while others, such as Charcoal Business and Legislation for Deforestation/Afforestation, did not show such potential. A follow-up survey with workshop participants showed that they were following the Action Plan, confirming the preference for the short-term policy proposal pathways.

In this study we look at everyday politics of electric bike mobility by exploring the social practices of e-bike users in order to understand the role of e-bikes in emerging low-carbon mobility system in China, asking 'where is the politics of the E2W in contemporary China?' We explore the underlying political tensions in electric two-wheeler mobility by examining family and informal e-bike journeys. We argue that 'civilizational' government perspective provides a new way of thinking about politics of mobility and system transition in China. ; info:eu-repo/semantics/publishedVersion

Developing administrative and financial mechanisms to achieve transparency and compliance with legal frameworks related to mine operation and closure is a major challenge. Ensuring the appropriate level of disclosure, transparency, and accountability of all compliant and non-compliant parties, and accessibility of this information to external interested parties is a cornerstone of achieving a well-governed minerals sector. This research investigates mining company voluntary environmental disclosures in Zambia as an indicator of how the EITI (Extractive Industry Transparency Initiative) may or may not achieve transparency and accountability. Our research findings drew on three sources: literature review, qualitative primary data with EITI and government officials and content analysis to compare public environmental reporting via company websites of a total of 27 mining companies operating in Zambia. Our analysis found that non-EITI and EITI selected companies disclose similar provisions for environmental liabilities at country, subsidiary, or multinational level. While EITI compliance may improve the environmental financial disclosure by mining companies, the detail and specificity of the voluntarily disclosed information is insufficiently transparent to third parties investigating whether governments and companies are compliant with the law in terms of environmental and governance considerations. We propose solutions to achieve transparency in practice by linking aggregated international voluntary initiatives (akin to the EITI) with mandatory jurisdiction-level reforms in mining financial securities and mine closure legislation accounted at the tenement level that is publicly available. Such reforms enable both independent accounting of financial transactions and improved national capacity for minerals sector governance that attracts international investment and incentivises an innovative, environmentally sustainable, and an economically beneficial mining industry. ; info:eu-repo/semantics/acceptedVersion

The problematic of Contaminants of Emerging Concern (CEC) in the European Union (EU) surface water has been reported over the last decades as well as CEC's potential impact on human health and the environment. The Water Framework Directive (2000/60/EC; WFD) is the main EU Directive for the protection of aquatic environments since it came in force. This Directive requires the monitoring of 45 priority substances regarding their environmental quality standards in order to achieve the good chemical status of water bodies until 2027. The last revision of the WFD in 2015 showed that Member States have not met the targets yet. The present dissertation aims to analyse whether WFD has been efficient enough to protect the aquatic ecosystems against CEC and evaluate if the environmental objectives will be complied until its last revision. The Netherlands was used as the case study. Interviews were carried out to 13 employees of the different layers in the Dutch water management system. Based on results obtained, it was concluded that the WFD has been the main European water legislation used to protect the aquatic environment from the occurrence of CEC in the last years. The Directive have created awareness and encourages Member States to take actions, however, some issues were identified. The conclusion is that WFD has not been efficient enough in the protection of aquatic environments against CEC. Although it is difficult to predict its success in 2027, two possible scenarios were identified. In the end, it was suggested a consistent assessment of CEC in aquatic environments, connection of WFD goals with EU's chemicals regulations, collaboration between all interested parties and an integrated strategy to WFD implementation in the Member States.

During the last two decades, EU legislation has put increasing pressure on member countries to achieve specified recycling targets for municipal household waste. These targets can be obtained in various ways choosing collection methods, separation methods, decentral or central logistic systems, etc. This paper compares municipal solid waste (MSW) management practices in various EU countries to identify the characteristics and key issues from a waste management and reverse logistics point of view. Further, we investigate literature on modelling municipal solid waste logistics in general. Comparing issues addressed in literature with the identified issues in practice result in a research agenda for modelling municipal solid waste logistics in Europe. We conclude that waste recycling is a multi-disciplinary problem that needs to be considered at different decision levels simultaneously. A holistic view and taking into account the characteristics of different waste types are necessary when modelling a reverse supply chain for MSW recycling. ; info:eu-repo/semantics/acceptedVersion

With the continuous rise of energy demand at a global scale and, the significant environmental impacts that the current energy sector causes, political decision-makers feel the need to increasingly invest in renewable energy sources, such as solar and wind energy, and find new ways to produce electricity with minimal environmental impact. The use of human movement to produce energy has already been a study subject, but with very few applications in the current market. This is mainly due to the relation between the investment costs and the electric output that current generators are able to produce. A scarcity of studies about the economic potential of these technologies is noted, which contributes to the weak interest of potential investors in their implementation. In this work an attempt is made to synthesize the results related to the analysis of the economic aspects associated to the technologies that use human motion, which already have real-life applications and have been extensively studied. Simultaneously the concept is developed, and a prototype is constructed of a system capable of using linear human movement, of which the performance is evaluated. As such, it becomes possible to compare the electric output of the rotational system, based on existing literature, with the output of the linear system based on the results acquired during the preliminary tests of a developed prototype. These values are used to calculate the reduction of greenhouse gas emissions that these systems enable. The experiments with the prototype were developed in a gymnasium, because these establishments concentrate a considerable amount of daily human motion. Currently, that movement is wasted in the machine's resistance. Meanwhile, the economic analysis and potential GHG savings of these systems are studied in four different gymnasiums with varying characteristics. It was determined that the use of rotational human motion to produce electric energy has a considerable economic potential in the current market, which is supported by the fact that a few establishments have already incorporated equipment that permit their exploitation. However, linear human movement is incapable of reaching an acceptable return period in almost all scenarios. Only large-scale gymnasium, such as Be-Fit Setúbal, possess the capacity to adopt this technology and reach a return period with economic viability

Este trabajo pretende hacer una reflexión sobre la importancia de los espacios de transición en los Equipamientos Colectivos, más exactamente los Centros Cívicos, la sinergia con el espacio público y los efectos que tienen en las dinámicas sociales en las ciudades y los barrios. Los equipamientos colectivos son un componente importante en la planeación de las ciudades. Su principal función ha sido la de ofrecer servicios para los ciudadanos por medio de espacios que promueven actividades, reunión, participación y encuentro. Para lograrlo, deben en su mayoría estar acompañados de componentes que aseguren la accesibilidad y cobertura equilibrada en el territorio. Se entienden por esos componentes, al espacio público de calidad, la accesibilidad por medio de transporte público y privado, la calidad en la configuración de los espacios, y la igualdad de condiciones, que permiten el acceso a todos los ciudadanos sin importar edad, raza, género y condición física, promoviendo inclusión y generando una cohesión social. Son estos componentes los que serán profundizados en este trabajo, y se apoyarán en un análisis realizado en una escala mas reducida, de 1:1, sobre el edificio, los Centros Cívicos, y la simbiosis con el Espacio Público, la Morfología y el Entorno. Identificando el potencial que tienen estos componentes cuándo son de verdad pensados para las personas y se aprovecha la función social que cumplen en el territorio. Para realizar este análisis se decidió escoger una Ciudad como base principal de estudio, donde el desarrollo de la ciudad esté o haya estado fundamentada la participación social y su principal objetivo sea mejorar la calidad de vida de sus habitantes. La Ciudad escogida es Barcelona, aunque conocida por sus transformaciones e innovaciones urbanísticas, aún no ha sido completamente explorada desde la completa red de equipamientos que históricamente ha estado ligada con la democracia de su territorio. Esta es una de sus fortalezas y hace de esta ciudad un buen ejemplo para estudiar y analizar. Este gran laboratorio, cómo es la Barcelona, será usado en este trabajo para estudiar y encontrar esos puntos de convergencia, donde la arquitectura promueve las interacciones, cumple la función de integrador y logra generar o influir positivamente en el proceso de apropiación espacial por parte de los ciudadanos. Con el fin de identificar fortalezas, debilidades o potencialidades en los equipamientos colectivos y su verdadero aporte a la cohesión social del territorio. Entendiendo que al final lo que hace la diferencia es la manera de implantarlo, pues el concepto o tipología ya está un poco más desarrollado.